改性玉米芯法吸附水中Zn2+的研究

Adsorption of Zn2+ from Water by Modified Corncob

重金属污染是环境问题的一个重要方面。为了探明生物吸附剂对水体中重金属离子的净化作用,通过微波辐照、酸碱及NaCl浸泡对玉米芯改性,以改性玉米芯对Zn2+的吸附率作为参考指标,运用控制变量法确定最佳改性条件为:微波照射功率280 W,辐照时间5 min,氯化钠质量浓度0.3%。改性玉米芯对水中Zn2+的最佳吸附条件为:玉米芯粒径为1.5 mm,用量20 g/L,吸附时间30 min,摇床转速180 r/min,ZnCl溶液pH为6左右。结果表明,改性玉米芯对低浓度Zn2+的吸附率达90%以上。可见,改性玉米芯对水体中重金属(锌)具有较好地吸附性能。

Heavy metal pollution is one of the important parts of environmental problems. In order to find out the bio- logical adsorbent for the purification effect of heavy metal ions in water, the microwave irradiation, as well as the im- mersion in HCl, NaOH and NaCl, was used to modify corncob respectively. The experiment used method of control variables, and the modified corncob adsorption rate of Zn2+ was the reference index. According to the results, the best modified condition was as follows: The power of microwave irradiation was 280 W, the time of microwave irradiation was 5 min, and the concentration of sodium chloride solutions was 0.3%. And the best adsorption condition was as fol- lows: the diameter of corncob was about 1.5 mm, the dosage was 20 g/L, the adsorption time was 30 min, the shaking speed was 180 r/min, and the pH value of liquor zinc chloride was about 6. The results showed that modified corncob adsorption rate of Zn2+ was more than 90% at low concentrations. In conclusion, it is a good adsorption property of heavy metal (zinc) in water by modified corncob.